For questions on dice, a small throwable object with multiple resting positions, used for generating random numbers. This makes dice suitable as gambling devices for games like craps, or for use in non-gambling tabletop games.

learn more… | top users | synonyms

1
vote
2answers
26 views

What is the probability of two dice getting a sum of 7 without a two?

I am currently working on conditional probability and I am somewhat confused about how exactly to complete this problem. I know that to find conditional probability that you utilize: $$P(A|B) = ...
-2
votes
1answer
24 views

Simple dice probability question [on hold]

Just a simple quick question. Five dice are thrown at the same time, all results are independent of each other. The dice are regular dice, with 6 sides. What is the probability that exactly three ...
3
votes
1answer
39 views

A fair die is rolled nine times. What is the probability that 1 appears three times, 2 and 3 each appear twice, 4 and 5 once and 6 not at all?

A fair die is rolled nine times. What is the probability that 1 appears three times, 2 and 3 each appear twice, 4 and 5 once and 6 not at all? My approach is fairly simple. The dice is fair, so we ...
1
vote
1answer
31 views

Optimal strategy in the following game:

In this game, 12 hidden D6s are rolled and summed. The player is given the total of the rolled dice. The player will then guess a number from 1 to 6. If there is a unrevealed dice with that number, ...
1
vote
0answers
42 views

Expected number of rolls on a 200 sided die to roll a 1? [duplicate]

We have a 200 sided fair die with faces numbered 1 through 200 and want to know how many rolls are expected to roll a 1. How would I go about calculating this?
0
votes
1answer
51 views

What's more likely with 7 dice - Straight, Full House, or 3-of-a-Kind

Here's a problem I'm having. I have 7 dice. I want to rank the difficulty of achieving a particular 5 dice combination after all 7 dice have been rolled. A straight is when at least 5 of the seven ...
0
votes
1answer
44 views

Dice Probabilities - How often does 3, 4, 5 show up in 5 dice on one roll?

I want to find out the probability for rolling 5 dice and the result containing at least 3, 4, and 5 without caring what the other 2 numbers are. I'm not very familiar with this kind of probability so ...
-1
votes
1answer
37 views

Is this Event Mutally Exclusive?

I am trying to calculate the following, however I'm unsure on whether this event would be Mutally Exclusive or Independent. Can someone help with finding the probability of the Intersection? P(A) ...
2
votes
3answers
42 views

How to handle dice probability? ie, how much more likely would 3 six sided dice give a higher sum than 3 four sided dice?

I am playing at making my own table-top gaming system/rules and I wanted to have a better handle on how likely different dice combinations will give a higher result than one another. I know that a six ...
2
votes
5answers
132 views

Dice roll probability, at least 9 total?

If I have two dice with $6$ sides each, what is the probability of me rolling atleast $9$ total? I think I'm correct when thinking that the probability of rolling a $9$ is $\frac{4}{36}$, that is ...
-1
votes
1answer
33 views

Normal distribution with dice

I'm wondering how to control the normal distribution that comes from summing dice rolls only using different numbers of dice, different combination of types of dice (d4, d6, d8, d10, d12, d20) and ...
0
votes
0answers
34 views

Probability of succesful rolls of different sided dies

This seems so simple, but I'm not sure how to calculate it. I have one six-sided die and one 12-sided die. What is the probability that, on a roll of both dice, that the six-sided die will win? ...
0
votes
1answer
27 views

The name for predicting future rolls of dice based on the past

My friends and I were playing a game where you roll dice and you bet money on what picture it's going to land on and I began reasoning with myself that if I tallied up what pictures the dice landed on ...
0
votes
2answers
39 views

Expected number of rolls?

Suppose a fair six-sided die has the following sides: 1, 1, 1, 1, 4, 4. The die is rolled twice. The mixed outcomes [1,4] and [4,1] are considered "successes" while the outcomes [1,1] and [4,4] are ...
1
vote
2answers
45 views

Probability with a 7-sided dice

I have this : "We roll a 7-sided dice n times. What is the lower value of n to have 60% of chance to have 2 same value" And I don't know how I can resolve this ... I know that the result is 5 but ...
1
vote
1answer
35 views

expected number of gold you can collect.

expected number of gold you can collect. you have a six sided dice and n points 1 to n. there some golds in any points. initially you are in position 1. if you reach any point you can collect all the ...
2
votes
2answers
35 views

What are the chances of drawing this unique combination of 3 coloured dice from 6 dice?

I'm having trouble understanding why one (or both) of my methods is wrong. Here is the problem. Let's say I have 6 dice: 2 yellow, 2 green, 2 red. I'm going to draw 3 dice from the 6 dice, and I ...
1
vote
2answers
110 views

Why is the sum of the rolls of two dices a Binomial Distribution? What is defined as a success in this experiment?

I know that a Binomial Distribution, with parameters n and p, is the discrete probability distribution of the number of successes in a sequence of n independent yes/no experiments, each of which ...
1
vote
1answer
43 views

Propability of M-faced dice rolling a greater result than an N-faced dice ( M<N) and expected value of the absolute difference?

Hello I have a game-mechanic which goes like this: Two-sides are rolling numbers. The defender rolls between [1,Armor_Value] , attacker rolls between [1,Damage_Value]. If the attacker_roll> ...
1
vote
2answers
55 views

4 Sided dice - flawed logic?

If we had a 4 sided dice (numbers 1,2,3,4 on the faces) and rolled it 6 times and recorded the results. What would be the probability that we rolled the same number 3 or more times? (Such as rolling ...
0
votes
2answers
37 views

Chance of rolling one skull with these three dice?

Let's say I have three 6-sided dice. One is red, one is green, one is yellow. The red dice have 3 skulls on 3 of its faces, the other faces are blank. The green dice have 1 skull each. The yellow ...
0
votes
2answers
26 views

What are the chances of drawing 2 shotguns in Zombie Dice in this situation?

I'm rusty on probability and, even so, I don't think I know how to deal with this situation. Here's the problem. Let's say I have a cup of $n$ dice. Each dice face has either a shotgun, a brain, or ...
1
vote
1answer
41 views

Dice rolls probability

Given a six-faced die with six distinctly marked faces, what is the probability that a toss will turn-up any one of the six faces. If three of the six faces are red and three blue, what is the ...
1
vote
0answers
31 views

Estimating the number of sides of a die

A friend of mine inspired this question: Given a fair die, can one accurately estimate (within some margin) the size of the die given enough rolls? For example: If I roll a die 1000 times and all the ...
1
vote
2answers
49 views

Why are the probability of rolling the same number twice and the probability of rolling pairs different?

Two scenarios: 1. Using one die, roll a 6 twice. $\frac16\times\frac16=\frac1{36}$ Rolling two dice roll the same number (a pair). $\frac6{36}=\frac16$ Why are these two probabilities ...
0
votes
2answers
48 views

Probability with 8 number of dice

Eight identical dice are rolled simultaneously. In how many possible outcomes each of the six numbers appears at least once? I got result as $\left(\dfrac 16\right)^8.$ And I think I missed some ...
1
vote
2answers
80 views

4 sided dice rolls - a probability question

If we had a 4 sided dice (numbers 1,2,3,4 on the faces) and rolled it 5 times and recorded the results. What would be the probability that we rolled the same number exactly 3 times? What about 3 or ...
0
votes
0answers
24 views

Probability and order

5 standard dice are rolled one at a time. What is the probability that the first two show ones and the next three do not? How do I distinguish the first two from the rest?
3
votes
1answer
183 views

Sum of resulting values of dice

We have thrown with $n$ dice. The sum of resulting values is $k$. We are looking for a function $f$ which gives the number of throws, with we can construct $k$ with $n$ dice. Some example for ...
1
vote
1answer
22 views

Expected amount of different diced numbers

I roll n regular, d-sided dices. What is the expected amount of different numbers on the dices? Or equivalently: What is the expected amount of numbers that have not been diced at all? Example: ...
0
votes
1answer
35 views

Dice Game - Probability Theory

There are many dice problems on here so there could be duplicate. If there is I apologize. Here is the question. The game is given as follows: you are given 5 dice, and the goal of the game is to get ...
1
vote
1answer
25 views

Finding an $f(x,y,n)$ such that $round[f(x,y,n)] = \lfloor\frac xn \rfloor + \lfloor\frac yn \rfloor$

Problem: I have an equation: $$\left\lfloor\frac xn\right\rfloor + \left\lfloor\frac yn\right\rfloor$$ I need to find an equation that does NOT use the floor function, but will take those same two ...
1
vote
1answer
34 views

Probability of hitting a certain sum with dices

Using $5$ $6$-faced dices, what's the probability of hitting a cumulative sum $S$, on a particular roll (each roll incorporates all $5$ dices ), if $15 \leq S\leq 20$? I reckon this particular ...
0
votes
2answers
64 views

Regarding combinatorics on dice…

The problem: If you are to roll a die five times, what is the probability the fifth die is not a repetition? Apparently the answer is $$\frac{6\cdot5^4}{6^5}$$ but I don't really see why. What ...
1
vote
0answers
74 views

Probability of rolling n dice to match another set of dice, d, given r rolls (like yahtzee)

(Note: I will eventually code this, but i'm primarily interested in the math behind it) I'm trying to create a function in Java to calculate the probability of getting a desired outcome from n rolled ...
0
votes
0answers
23 views

Multiple Dice Roll Probability (With Forumla)

I'm having the trouble of determining probability over multiple die rolls. I'm working with this formula. $$\frac{d20+d(\textrm{skill}) - \textrm{difficulty}}{d20+d(\textrm{skill})}$$ Basically, you ...
0
votes
2answers
60 views

Conditional probability rolling two dice

Two fair dice are rolled. What is the conditional probability that at least one lands on 6 given that the dice land on different numbers? I already know the answer, but am having some trouble ...
2
votes
1answer
36 views

Probability that less dice thrown will beat more dice thrown?

I'm trying to figure out a general equation to determine the probability that the sum of $m$ dice will be greater than the sum of $n$ dice, where $m < n$. For example, if I roll $4$ dice, what's ...
0
votes
1answer
61 views

Expected Value question regarding rolling a die multiple times

Let's say we play a game where we can roll a die up to two times. After each roll you may take the value you rolled, or roll again. What is the expected value assuming perfect play? Intuitively (not ...
0
votes
1answer
35 views

probability between two 6-sided dice and a 12-sided die

So if we have a game with player A who roll 2 dice with 6-sides and player B with one 12-sided die what is the probability to win for the player A and the probability to have a draw game. I have make ...
2
votes
2answers
46 views

Why is the probability of a dice being larger then the 2nd roll the same 2nd,3rd?

I understand that the probability of the first die roll being larger then the second is 5/12. I'm having a harder time understanding why, according to a small problem I wrote, the probability of the ...
1
vote
1answer
35 views

Finding solutions to an inequality(releating to statistics)

I am trying to solve the following problem. A person rolls 3 die, what is the probability that the sum of these die is less than or equal to 9? I have built the following inequality model ...
2
votes
1answer
47 views

Probability when two dice rolled. Why am I getting two different answers?

This is a homework problem that I've done two different ways. The question is P(Both dice show 4 or less $\bigcap$ No dice show a 1). I first separated them out to do P(Both dice show 4 or less) ...
0
votes
1answer
47 views

Probability of at least 3 sixes with 18 dice

I am trying to logically think about this, not to just apply formulas that are readily available for similar problems. Can anyone help explain the math behind finding the probability of getting at ...
1
vote
3answers
94 views

If a fair dice is rolled $5$ times, what is the probability that some number appears more than once?

A fair dice is rolled $5$ times. Find the probability that at least one of the possible outcomes $(1,2,3,4,5,6)$ appears more than once. A hint is the Birthday Problem. I keep getting $0.9074$, but ...
0
votes
2answers
32 views

Probability of 5 dices being 6s, given that I know 3 are 6s

Imagine a game with two players who each throw 5 dice and only they can see their own dice. If we roll and I see that I have 3 sixes, what are the probabilities that there are at least 5 sixes in ...
3
votes
2answers
38 views

Variance and expected values by dices, how does addition work?

I have read through some stuff and I am confused now. If we have a fair die and we just roll once, the expected value is going to be 3,5 and the variance is 2,916. Well, it is easy to count by one ...
1
vote
2answers
27 views

How to calculate the probability of a die with a wild side?

So I have a 6-sided die with 5 different values in 5 of their sides. Its sixth side can be treated as any of the other 5 values. So my question revolves around which is the probability of getting any ...
0
votes
2answers
93 views

Expected value problem on dice reroll

The question is here: Roll N* 3-sided dice(0,0,1), roll them twice and choose a better result, what is the expected value? If possible I would also like an answer for dice {0,1,2} or {1,2,3} if ...
10
votes
3answers
3k views

On average, how many times must I roll a dice until I get a 6?

On average, how many times must I roll a dice until I get a 6? I got this question from a book called Fifty Challenging Problems in Probability. The answer is 6, and I understand the solution the ...